An OFDM communication apparatus includes a determining section determine a number of known signals for transmission path estimation to be inserted in a transmit signal based on channel quality with respect to a communicating party, and a generating section performs inverse Fourier transform processing on an information signal and the number of known signals for transmission path estimation determined by the determining section and generates a transmit signal for the communicating party. The apparatus achieves both an improvement in demodulated signal error rate characteristics and an improvement in information signal transmission efficiency.